6780856409 has 4 divisors (see below), whose sum is σ = 6781375440. Its totient is φ = 6780337380.

The previous prime is 6780856367. The next prime is 6780856421. The reversal of 6780856409 is 9046580876.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6780856409 - 2⁸ = 6780856153 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6780856909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 239399 + ... + 266220.

It is an arithmetic number, because the mean of its divisors is an integer number (1695343860).

Almost surely, 2^6780856409 is an apocalyptic number.

It is an amenable number.

6780856409 is a deficient number, since it is larger than the sum of its proper divisors (519031).

6780856409 is a wasteful number, since it uses less digits than its factorization.

6780856409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519030.

The product of its (nonzero) digits is 2903040, while the sum is 53.

The square root of 6780856409 is about 82345.9556323199. The cubic root of 6780856409 is about 1892.7569489184.

The spelling of 6780856409 in words is "six billion, seven hundred eighty million, eight hundred fifty-six thousand, four hundred nine".